This application relates to image sensors, and more particularly, image sensors that have visible and near-infrared pixels.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with an array of image pixels arranged in pixel rows and pixel columns. The image pixels contain a photodiode for generating charge in response to light. Circuitry is commonly coupled to each pixel column for reading out image signals from the image pixels. A color filter element typically covers each photodiode.
Several image sensor applications (such as security cameras) require visible light and near-infrared (NIR) image sensor sensitivity at the same time. Conventional systems use a physically moveable IR filter to obtain near-infrared and visible light sensitivity. However, this is impractical and there is a strong need for a low-cost image sensor with both visible light and near-infrared (NIR) sensitivity.
It would therefore be desirable to provide image sensors with visible and near-infrared light sensitivity.